He's really not that hard but don't read any further if you want to figure it out yourself all you have to do is be about level 19 and make sure to have barret's Mindblow so you can steal its MP and it can't cast beta. As for getting across the swamp without facing the midgar zolom or riding a chocobo, if you wait until it's in the back of the left corner on your side you can just make it across.